Plant for burning waste

Abstract

A plant for burning waste which has a main combustion chamber to be chargedith the waste to be burnt and with fresh gases for burning the waste. From this main combustion chamber the burnt material and unburnt residual material including gases pass through a grate into a post-combustion chamber, the bottom of which is adapted to be closed, and which has lateral outlets for the waste gas. The post-combustion chamber which has a volume at least equalling the volume of the main combustion chamber has a wall structure extending from above into said post-combustion chamber for guiding gases passing through the grate toward the bottom of the post-combustion chamber. This wall structure is open at its lower end and is of highly heat resistant material as e.g. steel. The post-combustion chamber has a waste gas outlet through which the waste gas from the post-combustion chamber is discharged after it has, prior thereto, been purified by passing through filters between an outer wall and inner wall of the post-combustion chamber.

What we claim is: 
     
       1. A plant for burning waste, which includes: a main combustion chamber having inlet means for receiving waste to be burned and for receiving fresh gases for burning said waste, a post-combustion chamber arranged below said main combustion chamber and open at its top, means for normally providing a down draft through the main combustion chamber into said post-combustion chamber and including therewith a grate interposed between said main combustion chamber and said post-combustion chamber and forming the bottom of said main combustion chamber and the top of said post-combustion chamber, said post-combustion chamber having an opening in its bottom for discharging ashes and residues from the combustion in said main and post-combustion chambers and having a volume equalling at least the volume of said main combustion chamber, cover means for selectively closing said opening, said post-combustion chamber also being provided with outlet means for discharging waste gas from said post-combustion chamber and a wall structure of highly heat resistant material arranged within said post-combustion chamber and open at its bottom for guiding flue gases passing through said grate toward the bottom of said post-combustion chamber. 
     
     
       2. A plant according to claim 1, which includes restricting guiding plates arranged in the upper portion of the space defined by the inside of said wall structure for subjecting to turbulence the gases passing into said post-combustion chamber. 
     
     
       3. A plant according to claim 1, which includes conduit means leading into the upper portion of the space defined by the inside of said wall structure. 
     
     
       4. A plant according to claim 2, which includes conduit means for conveying fresh gases into said post-combustion chamber, said conduit means leading into said post-combustion chamber below said guiding plates. 
     
     
       5. A plant according to claim 4, in which a portion of said conduit means leading into said post-combustion chamber extends in countercurrent flow direction with regard to the downward flow direction of the gases passing through said grate. 
     
     
       6. A plant according to claim 1, in which the wall of said main combustion chamber is a double wall with its inner wall consisting of a highly heat-resistant material, and in which said inlet means for feeding fresh gases into said main combustion chamber leads into the upper portion of said main combustion chamber and is so arranged therein that said last mentioned fresh gas passes between said inner and outer walls of said double wall in upward direction prior to entering the chamber defined by said last mentioned inner wall. 
     
     
       7. A plant according to claim 1, in which said grate comprises at least two sections each of which is pivotable about one but a different axis toward the respective adjacent wall of said main combustion chamber. 
     
     
       8. A plant according to claim 7, in which the grate sections are provided with intermeshing teeth. 
     
     
       9. A plant according to claim 1, which includes waste gas filtering means arranged in said outlet means of said post-combustion chamber. 
     
     
       10. A plant according to claim 9, in which said waste gas filtering means include filtering mats of ceramic material arranged in said outlet means. 
     
     
       11. A plant according to claim 1, in which a portion of said outlet means of said post-combustion chamber is formed by the outer wall of said post-combustion chamber and is formed as a grate of steel. 
     
     
       12. A plant according to claim 1, in which a portion of said outlet means of said post-combustion chamber is formed by the outer wall of said post-combustion chamber and is formed as perforated plates of ceramic material.